If there is an unsaved content, the Sifr icon for "save/save as.../export..." is not shown as other activated icons in the toolbar in dark themes. The icon itself is bright highlighted but looks "cut" at the edges and not smooth like icons with activated status like spell checker or left alignment of paragraphs.
I know that the "save/save as" icon is different from the other icons I mentioned, nevertheless it should look more excellent as the other icons of the excellent Sifr icon theme do.

I can’t push to the Sifr repo at GitHub.com/libodesign, but I reexported the icon from saveexport.svg and pushed the result to LibreOffice (only the 16 × 16 icon was affected). I’ll backport this change to 5.3.3 as well.